Why does sex still hurt after the first time?

does it hurt when you apply pressure yourself? since y'all are new to sex y'all need to take it slow. have him do some oral stimulation before to make sure you are nice and wet, and unless his johnson is very large it shouldn't hurt when barely in, try touching yourself to see if you can recognize where the pain is coming from, if it persists i would say see your doctor to make sure its not major problem. Also, try taking a break and try it in a week to see if anything has changed.